Developer Reference

  • 0.9
  • 09/09/2020
  • Public Content
Contents

p?lasnbt

Computes the position of the sign bit of a floating-point number.

Syntax

void
pslasnbt
(
MKL_INT
*ieflag
);
void
pdlasnbt
(
MKL_INT
*ieflag
);
Include Files
  • mkl_scalapack.h
Description
The
p?lasnbt
function
finds the position of the signbit of a single/double precision floating point number. This
function
assumes IEEE arithmetic, and hence, tests only the 32-nd bit (for single precision) or 32-nd and 64-th bits (for double precision) as a possibility for the signbit.
sizeof(int)
is assumed equal to 4 bytes.
If a compile time flag (
NO_IEEE
) indicates that the machine does not have IEEE arithmetic,
ieflag
= 0
is returned.
Output Parameters
ieflag
This flag indicates the position of the signbit of any single/double precision floating point number.
ieflag
= 0
, if the compile time flag
NO_IEEE
indicates that the machine does not have IEEE arithmetic, or if
sizeof(int)
is different from 4 bytes.
ieflag
= 1
indicates that the signbit is the 32-nd bit for a single precision
function
.
In the case of a double precision
function
:
ieflag
= 1
indicates that the signbit is the 32-nd bit (Big Endian).
ieflag
= 2
indicates that the signbit is the 64-th bit (Little Endian).

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804